The present invention relates to a vehicle, which can enhance the operation capability over severe terrain and reduce fuel consumption. References to the “invention” herein should be understood to be references to one or more aspects of the invention.
Construction vehicles as construction equipments have been developed in various shapes to satisfy various demands for providing necessary functions at the work site under various environmental conditions and for effectively displaying individual functions even in severe conditions.
As a representative example of such construction vehicles, there are vehicles that are loaded therein and operated. Such vehicles are generally classified into an articulated dump truck and a rigid dump truck.
An articulated dump truck refers to a vehicle wherein one or more trailers accommodating loads are connected to one another. A rigid dump truck refers to a vehicle in the shape of a body. Specifically, the present invention relates to a rigid dump truck.
Such a vehicle is basically operated in a normal condition. When a vehicle is operated in severe conditions, however, there would be many difficulties in operation itself. Particularly, in the event a vehicle is operated in the area that the terrain is seriously curved or the ground is not firm, there would be substantial difficulties in operating the vehicle due to many variables. Below is an example of such case.
When the wheels of a vehicle pass over the ground that is neither flat nor firm, the center of gravity of the vehicle may be moved considerably toward one side. Thus, it would be difficult to keep its balance. In a worse case, it may lead to vehicle overturn. A repetitive operation in such terrain will cause a problem, such as giving a shock to a driver. Accordingly, safety and terrainability of a vehicle will be considerably lowered.
In addition, under this situation, several wheels fail to be in sufficient contact with the ground, and thus they cannot display their traction force or will be spinning with no traction, which may result in difficulty in operation.
In order to solve these problems, a leveling arrangement may be used. The leveling arrangement prevents the center of gravity of a vehicle from leaning rapidly toward one side on the ground that is not flat to secure stability of the vehicle. Specifically, the leveling arrangement regulates the height of the axle connected to each of the right and left wheels so that the vehicle maintains level.
However, if a vehicle is equipped with the leveling arrangement, the manufacturing costs will increase. Moreover, it is not easy to control the leveling arrangement, and it is not guaranteed that a vehicle equipped only with the leveling arrangement will be stably operated. Accordingly, an alternative is required.
When a vehicle is operated, it is important to prepare a measure for reduction in fuel consumption, as well as smooth steering or maintenance of vehicle stability. Normal vehicles are equipped with two or more pairs of wheels that are connected to the front and the rear. These wheels are connected to the axle fixed to the vehicle body to rotate around the rotational axis.
When a vehicle forming such wheels travels straight ahead, the wheels placed on the rear are operated to follow the route of the wheels placed on the front, in which case, the wheels will not be dragging. When traveling on a curve, the wheels will be dragging as the wheels do not roll toward the traveling direction. Since such wheel dragging considerably increases fuel consumption, a measure for solving this problem is required. Furthermore, these normal vehicles are difficult to be operated in the severe terrain, as stated above.
The present invention was designed to solve the aforesaid problems. The present invention discloses an example of a vehicle, wherein each wheel connected to a vehicle is individually suspended and steerable, and the route of the front and rear wheels are selectively controlled to minimize fuel consumption and enhance traction force.
A vehicle with a controllable wheel route according to a preferred example of the present invention comprises: a vehicle body; a first pair of wheels, which are individually suspended on both sides of the vehicle body to roll on the ground and can rotate around the vertical axis; a second pair of wheels, which are individually suspended on both sides of the vehicle to roll on the ground, can rotate around the vertical axis, and are placed in the back of the first wheels; a regulator, which regulates a steering angle of each of the first wheels and the second wheels around the vertical axis; a mode selector, which is configured to select a first mode and a second mode; and a controller, which received a first signal or a second signal from the mode selector and controls the regulator according to the received signal, wherein the second wheel route is regulated to be identical to the first wheel route in the first mode, and the second wheel mute is regulated to be different from the first wheel route in the second mode.
In the first mode, the regulator regulates the first wheels and the second wheels to be linearly arranged, without being rotated around the vertical axis.
To the contrary, the regulator in the first mode regulates the first wheels and the second wheels to be arranged on a curve which forms a concentric circle with the vehicle center route so that the steering angle of the first wheels and the second wheels, which are placed on the outer side of the curve, around the vertical axis is lower than the steering angle of the first wheels and the second wheels, which are placed on the inner side of the curve.
In a vehicle with a controllable wheel route according to the preferred example of the present invention, the regulator in the second mode regulates the second wheel route to repeatedly cross the first wheel route.
The regulator in the second mode regulates the first wheels to be arranged without being rotated around the vertical axis and the second wheels to repeat a clockwise rotation and a counterclockwise rotation around the vertical axis.
Unlike this, the regulator in the second mode regulates the second wheels to be arranged without being rotated around the vertical axis and the first wheels to repeat a clockwise rotation and a counterclockwise rotation around the vertical axis.
Furthermore, the regulator in the second mode, the steering angle of the first wheels and the second wheels around the vertical axis to be identical and to repeat a clockwise rotation and a counterclockwise rotation.
In a vehicle with a controllable wheel route according to a preferred example of the present invention, the regulator in the second mode regulates the second wheel route to be parallel with the first wheel route.
The vehicle further comprises a third pair of wheels, which are individually suspended on both sides of the vehicle body to roll on the ground, can rotate around the vertical axis, and are placed in the back of the second wheel. The regulator regulates the steering angle of the third wheels around the vertical axis. In the first mode, the regulator regulates the third wheel route to be identical to the first wheel route and the second wheel route. In the second mode, the regulator regulates the third wheel route to be different from the first wheel route and the second wheel route.
Further, the vehicle comprises a drive unit, which individually drives the first wheel, the second wheel, and the third wheel, and a transmission, which changes the speed of the first, second, and third wheels.
According to an example of the present invention as stated above, modes vary depending on terrain conditions or operation conditions. Specifically, in the first mode, the second wheel route and the first wheel route are regulated to be identical to minimize rolling friction in the second wheel, which results in reducing fuel consumption. In the second mode, the second wheel route and the first wheel route are regulated to be different to increase traction force of the second wheel, which results in easily operating a vehicle. That is the vehicle of the present invention achieves both a lower fuel consumption and easy operation of a vehicle.
Further, unlike the conventional vehicle, wherein the load is being taken by the vehicle body frame, which makes a design to counteract bending and torsional stresses necessary, which in turn results in increasing the vehicle weight and fuel consumption, the vehicle in the present invention is designed such that the load is mostly supported directly above the wheels, which makes a lighter frame design possible and due to decreased total mass results in an advantage of reducing fuel consumption.